The most senior Iranian to visit Washington in 25 years said Thursday the two nations' long estrangement should be repaired through dialogue instead of threats, as world powers moved closer to imposing punishments on Iran over its disputed nuclear program.

Mohammed Khatami, a two-term Iranian president once seen as the harbinger of moderation and better relations with the United States, also said three of the nations that have offered to bargain with Iran may be willing to change the terms.

Khatami said Russia, China and France would agree to negotiate without preconditions that Iran has said are unacceptable, but he did not elaborate. Those nations, with the United States, Britain and Germany, have offered trade and aid incentives to Iran if it rolls back a nuclear program that the West fears could produce a weapon, with United Nations sanctions the price of refusal.

The group agreed that Iran must shelve its uranium enrichment program before talks on the package could start and no nations have said publicly that they would reconsider.

"Even now I believe that relations between our two respective governments should be resolved through dialogue," Khatami said during a news conference with U.S. and other reporters. He spoke through a translator.

"Using violence by every side and violent language by every side is not conducive to dialogue and it will increase and exacerbate the problems," Khatami said.